JP3210706B2 - Optical fiber element containing polyacrylate coating layer reticulated by ultraviolet irradiation and hydrogen absorbing buffer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to an optical fiber element comprising a coating layer of reticulated polyacrylate with H ₂ absorption slow衡剤and ultraviolet radiation.

[0002]

2. Description of the Related Art In the specification of the present application, "optical fiber element" is used.
The expression refers to elements for the transmission and / or processing of optical signals, such as fiber optic cables, splices for fiber optic cables, terminals for fiber optic cables, amplifiers using active core fiber optics, optoelectronic repeaters, fiber optics. Used to indicate sensors and the like.

[0003] It is known that optical fibers are coated with a protective sheath of polyacrylate ester which has been reticulated by UV irradiation in order to allow its handling.

[0004] The sheath of the polyacrylate ester reticulated by the above-mentioned ultraviolet irradiation is preferably a primary coating,
Consists of a secondary coating, and an optional outer colored layer.

[0005] The armor is usually obtained from a mixture of a prepolymer (oligomer) containing an acrylic base with a reactive functional diluent, a photo-initiator and other secondary additives. Depending on the photoinitiator used, it is also often necessary to add an activator. In the case of primary and secondary coatings, the respective mixtures are added during the spinning process and are irradiated with ultraviolet light to reticulate on the line. On the other hand, in the case of a colored layer, it is preferred to apply a suitable mixture in a later step to the fibers already protected by the primary and secondary layers.

It is also known that other layers of polyacrylates reticulated by ultraviolet irradiation may be included in fiber optic elements of more complex construction, for example fiber optic tape.

Finally, it is known that hydrogen has a detrimental effect on optical fibers and reduces their efficiency. Therefore, it has been proposed to include in the fiber optic element some compositions that are capable of trapping hydrogen before it has a deleterious effect on the fiber. Such compositions are simplified in the present specification is expressed as "H ₂ absorption slow衡剤".

[0008]

SUMMARY OF THE INVENTION
And at least one unsaturated organic compound of silicon, it has been developed at least one H ₂ absorption slow衡剤made from a composition comprising a hydrogenation catalyst selected from the group consisting of a salt and an organic compound of a transition metal. Examples of these compositions are described in U.S. Pat.
No. 88,889 and Italian patent application 20,8
Nos. 33 and 20,834 (both filed July 2, 1990).

Unexpectedly, certain polyacrylates reticulated by ultraviolet irradiation have
It has been observed that it interferes with the action of hydrogenation catalysts based on transition metals of H ₂ absorption buffers. Such cause was implemented in a particular purpose study interference effects of inactivating and H ₂ absorption slow衡剤is not an intrinsic property to the polyacrylic acid esters, in order to promote the UV irradiation It was found to be in certain compounds added.

[0010] In particular, such interferences are due to certain photoinitiators of UV irradiation reticulation and / or certain activators used with the photoinitiators, and in some cases their amounts are reduced by UV radiation. Despite the fact that it is of the order of only 10 ^-4 to 10 ^-5 parts by weight, based on the amount of H ₂ absorption buffer in contact with the polyacrylates reticulated by irradiation, It turned out to be.

[0011] Interference with the operation of the hydrogenation catalyst is caused by the fact that the interfering photoinitiator and / or activator is contained only in the primary coating of the fiber and the secondary coating in direct contact with the H ₂ absorption buffer. It has also been found that it happens when it doesn't exist.

[0012]

Photo initiator and its activator to Means for Solving the Problems] Inactivation of H ₂ absorption slow衡剤is confirmed by the test. This test will be described in detail later. Using this test method, the amount of hydrogen absorbed with H ₂ absorption gentle衡剤, 30 days at 100 ° C. in saturated air atmosphere with water vapor at 150 mbar, polyacrylic acid ester which is reticulated by ultraviolet irradiation It can be measured before and after contact with. On the basis of the test results obtained, the photoinitiator and / or its activator are polyacrylates reticulated by UV irradiation for 30 days at 100 ° C. in an air atmosphere saturated with steam at 150 mbar. When the residual absorption capacity of the H ₂ absorption buffer is more than 70% when it is brought into contact with, it is considered that it has no inactivating effect.

According to the present invention, there is provided an optical fiber element comprising at least one coating layer and at least one H ₂ absorber, wherein the H ₂ absorber substantially comprises at least one silicon absorber. And an at least one hydrogenation catalyst selected from the group consisting of a transition metal salt and an organic compound, wherein the coating layer is a polyacrylic acid that has been reticulated by ultraviolet irradiation. An ester, wherein the polyacrylate comprises at least one photoinitiator for UV irradiation reticulation and an activator for the photoinitiator, if present, wherein the photoinitiator comprises nitrogen. Contains no phosphorus or sulfur atoms, does not require the presence of an amino activator, and the photoinitiator and its activator, if present, are saturated with steam at 150 mbar. 30 days at 100 ° C. in an air atmosphere, which the reduction rate of the hydrogen absorption capacity of the polyacrylic acid ester and contact with and H ₂ absorption slow衡剤containing these photo initiator and activator to less than 30% An optical fiber element is provided, characterized in that:

According to the present invention, there is also provided an optical fiber cable comprising at least one coating layer and at least one H ₂ absorbing buffer, wherein the H ₂ absorbing buffer is substantially at least one type. A composition comprising an unsaturated organic compound of silicon, and at least one hydrogenation catalyst selected from the group consisting of a salt of a transition metal and an organic compound, wherein the coating layer is a polyacrylic reticulated by ultraviolet irradiation. An acid ester, wherein the polyacrylate comprises at least one photoinitiator for UV irradiation reticulation and an activator for the photoinitiator, if present, wherein the photoinitiator comprises: Contains no nitrogen, phosphorus or sulfur atoms and does not require the presence of an amino activator, and the photoinitiator and its activator (if present)
100 mbar in air atmosphere saturated with water vapor
30% at 30 ° C. for reducing the hydrogen absorption capacity of the H ₂ absorption buffer in contact with the polyacrylate containing the photoinitiator and the activator to less than 30%. An optical fiber cable is provided.

After the photoinitiator and its activator (if present) have been contacted with their containing polyacrylates for 30 days at 100 ° C. in an air atmosphere saturated with steam at 150 mbar, the hydrogen absorption capacity a typical example of H ₂ absorption slow衡剤that suitable for being to determine whether to reduce is disclosed in example 1 of U.S. Patent No. 4,688,889. The H ₂ absorption buffer is
(A) 90 parts by weight of a vinyl-terminated dimethylsiloxane, which does not have an unsaturated chain and has a product 10
Containing 7.4 mmol of unsaturated groups per 0 g,
(B) 0.2 parts by weight of palladium powder having an average diameter of 48 microns; and (c) 10 parts by weight of colloidal silica;
Substantially constituted by Examples of the manufacture of optical cables and their components useful in connection with the present invention include U.S. Pat. No. 4,688,889, British Patent 2,172,410,
European Patent Publication 280,275, French Patent Publication 2,200,535, British Patent 1,598,540,
British Patent 2,021,282, British Patent 2,099,17
No. 3, UK Patent 2,164,471, UK Patent 2,17
0,921, British Patent 2,174,822, U.S. Patent 4,143,942, U.S. Patent 4,153,332, U.S. Patent 4,199,224, U.S. Patent 4,491,386
No. 4,491,387, U.S. Pat.
590 and U.S. Pat. No. 4,690,498.

Examples of suitable photoinitiators according to the invention are those which do not contain any nitrogen, phosphorus or sulfur atoms in their molecules and which do not require the addition of amino activators. .

Examples of suitable photoinitiators which do not contain any nitrogen, phosphorus or sulfur atoms in their molecule and which do not require the addition of amino activators are benzoin and its alkyl ethers, acetophenone, Dialkyl acetophenone, anthraquinone and its derivatives.

A typical example of the photo initiator according to the present invention is
Benzophenone, diethoxyacetophenone, dimethoxyphenylacetophenone, hydroxycyclohexylphenyl ketone, and 2-hydroxy-2-methyl-1-
Phenylpropanone.

The following tests and examples have been used to illustrate the invention, but the invention is not limited thereto.

[0020]

Hydrogen absorption capacity of the portion of Example Test H ₂ absorption loose衡剤, by measuring the decrease in pressure in a closed vessel containing of H ₂ absorption slow衡剤tested in a hydrogen atmosphere evaluated. The equipment used is a commercially available automatic equipment for measuring pressures in the range 1000-1 mbar. The device has two valves (one is a pin type that regulates the supply of hydrogen,
The other is an assembly of a fixed volume chamber with a conventional pressure transducer E8510 connected to a commercially available digital reader) and a commercial pressure transducer E8510 connected to a commercially available digital reader. Both are Edwards Alto Vuoto S.
Manufactured by PA. Inside the device is a glass container. The control unit, which gives a digital reading of the pressure, has a resolution of 1 mbar and the indication of the pressure is independent of the gas composition and the atmospheric pressure. The test was performed at a constant temperature of 23 ° C.

After the weight of the glass container was measured to an accuracy of 0.01 g (weight A), the H ₂ absorption buffer of interest was placed in the container. The weight of the glass container was then measured again (weight B).

The glass container holding the target H ₂ absorption buffer was placed in the apparatus and evacuated for about 1-2 hours. After placing the system under static vacuum for at least 12 hours, the vessel was connected to a hydrogen cylinder until the digital pressure indicator indicated the desired pressure (generally 500-1000 mbar).

The hydrogen cylinder cock was closed and the time and hydrogen pressure were recorded.

After 24 hours, the pressure of the remaining hydrogen was read.

The hydrogen absorption capacity in Ncm ³ / g is calculated using the following equation.

[0026] P = initial hydrogen pressure Pr = pressure of remaining hydrogen after 24 hours of test C = temperature during test (° C.) V = free volume of apparatus after loading with H ₂ absorption buffer of interest B = H ₂ Weight of glass container with absorption buffer A = Weight of empty glass container H ₂ For each sample of absorption buffer, the above test was performed twice, and the average of the two values obtained was calculated. did.

The above tests were performed before and after the optical fiber coated or having a coating of the coating material according to the method described below was contacted with the H ₂ absorbing buffer.

A) Coated Fiber A portion of the coated optical fiber having a length according to the fiber / H ₂ absorption buffer ratio present in the optical fiber cable was used. Normally, such ratio, H ₂ absorption slow衡剤per meter of the optical cable is 2g.

In the case of a single-fiber optical cable, the coated optical fiber was coated with an H ₂ absorption buffer whose hydrogen absorption capacity was previously determined by the method described above. The coated optical fiber thus treated was aged at 100 ° C. in the presence of air (150 mbar) and saturated steam in a large sealed test tube. After one month, the H ₂ absorption buffer was recovered and its residual hydrogen absorption capacity was measured as described above.

B) Coating material Three film-like samples having a thickness of 10 to 20 mm and being reticulated in the depth direction by ultraviolet irradiation were prepared. These are the materials used to form the primary coating, the secondary coating and the colored layer of the optical fiber. These samples were made with an amount of material that covered approximately 5 meters of optical fiber. Each sample was coated with 10 g of an H ₂ absorption buffer whose hydrogen absorption capacity was previously measured by the method described above. Each sample was aged under the conditions described in a) above. After one month, the H ₂ absorption buffer was recovered and its residual hydrogen absorption capacity was measured as described above.

Example 1 Mixture for forming a non-interfering primary coating layer : Silicon acrylate (EBECRYL® 350, Radcure Specialties, USA) 55 g Aliphatic urethane acrylate (EBECRYL® 230, Radcure Specialties) Co., USA) 10 g Hexanediol diacrylate (HDDA) 15 g Isobornyl acrylate 15 g Diethoxyacetophenone 5 g Hydrogen absorption capacity of H ₂ absorption buffer part : Initial = 1.65 Ncm ³ / g Final = 1.38 Ncm ³ / g Example 2 Mixture for forming an interfering primary coating layer : Silicon acrylate (EBECRYL® 350, Radcure Specialties, USA) 55 g Aliphatic urethane acrylate (EBECRYL® 230, Radcure Specialties, United States) 10 g Hexanediol diacrylate (HDDA) 8 g Isobornyl acrylic Over preparative 15g benzophenone 5g aminoacrylate (UVECRYL (TM) P115, Radcure Specialties Inc., USA) 7 g H ₂ hydrogen absorption capacity of the portion of the absorbent slow衡剤: initial = 1.65Ncm ³ / g final = 0.35Ncm ³ / g Comparison of Examples 1 and 2 shows that the interfering effect may be due to the amino acrylate (activator).

Example 3 Mixture for forming a non-interfering secondary coating layer : Epoxy acrylate (EBECRYL® 600, Radcure Specialties, USA) 45 g Aromatic urethane acrylate (EBECRYL® 210, Radcure) (Specialties, USA) 5 g Methacrylic acid 15 g Trimethylolpropane triacrylate (TMPTA) 20 g Tripropylene glycol diacrylate (TPGDA) 5 g Dimethoxyphenyl acetophenone 10 g Hydrogen absorption capacity of the H ₂ absorption buffer part : Initial = 1.70 Ncm ³ / g final = 1.46 Ncm ³ / g Example 4 Mixture for forming a layer of a disturbing secondary coating : Epoxy acrylate (EBECRYL ™ 600, Radcure Specialties, USA) 45 g aromatic urethane acrylate ( EBECRYL (TM) 210, Radcure Specialties, USA 7g meta Acrylic acid 15g trimethylolpropane triacrylate (TMPTA) 20 g tripropylene glycol diacrylate (TPGDA) 5g hydroxypropyl phenyl ketone 5g isopropylthioxanthone 3 g H ₂ hydrogen absorption capacity of the portion of the absorbent slow衡剤: initial = 1.70Ncm ³ / g Final = 0.40 Ncm ³ / g Comparing Examples 3 and 4, it can be seen that the interfering effect may be due to isopropylthioxanthone (activator).

Example 5 Mixture to form a colorless (ink) layer without interference : Polyester urethane acrylate (EBECRYL ™ 810, Radcure Specialties, USA) 44 g Tripropylene glycol diacrylate (TPGDA) 10 g Tri Methylolpropane triacrylate (TMPTA) 25 g White pigment (TiO ₂ ) 5 g N-vinyl-2-pyrrolidone (diluent) 10 g 2-hydroxy-2-methyl-1-phenylpropane 6 g Hydrogen in the portion of H ₂ absorption buffer Absorption capacity : Initial = 1.70 Ncm ³ / g Final = 1.50 Ncm ³ / g Example 6 Mixture for forming a disturbing colored (ink) layer : Polyester urethane acrylate (EBECRYL® 810, Radcure Specialtie) Company, USA) 44 g Tripropylene glycol diacrylate (TPGDA) 10 g Chi triacrylate (TMPTA) 25 g white pigment (TiO ₂₎ 5 g N-vinyl-2-pyrrolidone 9g benzophenone 4g 4,4'-bis (dimethylamino) hydrogen absorption capacity of benzophenone 3 g H ₂ absorption slow衡剤part of: Initial = 1.70 Ncm ³ / g Final = 0.48 Ncm ³ / g Comparing Examples 5 and 6, it is possible that the interfering effect may be due to 4,4-bis (dimethylamino) benzophenone (photoinitiator) Understand.

──────────────────────────────────────────────────の Continuation of the front page (73) Patent holder 591011856 Pirelli Cavie Systeme S. p. A (72) Inventor Antonio Campana Italy 20161 Via Vicenzo da Seregno, Milan 18 (56) References JP-A-60-145938 (JP, A) JP-A-60-239702 (JP, A) JP-A-62-245208 (JP, A) JP-A-62-257944 (JP, A) JP-A-1-193706 (JP, A) JP-A-4-274205 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02B 6/00-6/54 C03C 25/24

Claims (4)

(57) [Claims] At least one covering layer and at least one
A fiber optic element comprising a species H ₂ absorption slow衡剤,
The H ₂ absorption slow衡剤is substantially compositions comprising the at least one unsaturated organic compound of silicon and at least one hydrogenation catalyst selected from the group consisting of a salt and an organic compound of a transition metal Wherein said coating layer comprises a polyacrylate ester reticulated by ultraviolet radiation, said polyacrylate ester comprising at least one photoinitiator for reticulation by ultraviolet radiation and a photoinitiator for said photoinitiator. An activator (if present), said photoinitiator does not contain nitrogen, phosphorus or sulfur atoms and does not require the presence of an amino activator, and said photoinitiator and its activator (present Is in contact with these polyacrylates containing these photoinitiators and activators for 30 days at 100 ° C. in an air atmosphere saturated with water vapor at 150 mbar. Characterized in that the reduction rate of the hydrogen absorption capacity of H ₂ absorption slow衡剤is to less than 30%,
Fiber optic element. 2. The optical fiber element according to claim 1, wherein the photoinitiator is selected from benzoin and its alkyl ethers, acetophenone, dialkylacetophenone, anthraquinone and its derivatives. 3. The photoinitiator is selected from benzophenone, diethoxyacetophenone, dimethoxyphenylacetophenone, hydroxycyclohexylphenylketone, and 2-hydroxy-2-methyl-1-phenylpropanone. Item 3. The optical fiber element according to item 1 or 2. 4. An optical fiber cable comprising the optical fiber element according to claim 1.